The present invention relates generally to packages for integrated circuits, and more particularly to such packages in which a surface of the integrated circuit is provided with a pre-attached conductive mounting media.
In the manufacture of integrated circuits, wafers containing many separate integrated circuits are fabricated and then cut into individual circuits, often individually referred to as die. Each die is individually packaged, using any one of a variety of known techniques. During packaging, electrically conductive leads are attached to electrical contacts of the die by well known techniques, such as wire bonding or tape automated bonding. A particularly desirable lead attachment technique is disclosed in my copending application of Ser. No. 365,686, filed Apr. 5, 1982, now U.S. Pat. No. 4,390,598, entitled "Lead Format For Tape Automated Bond", assigned to the assignee of the current application and hereby incorporated by reference. After the assembly of the die and the conductive leads is completed, the resulting assembly is then usually encapsulated in epoxy or some other enclosure for protection.
Referring more particularly to the typical die, one surface of the die includes a plurality of the electrical contacts to which these leads are attached while the opposing surface of the die is generally conductively bonded to a substrate by conventional means. For example, as described in my previously mentioned copending patent application, one technique is to employ a thin layer of conductive polymide paste placed on the substrate and then apply heat to cure the paste and attach the die to the substrate. Thus, although the electrical connections necessary on one side of the die can be made simply and in an automated fashion, the steps involved in attaching the die to the substrate, often referred to as die-attach, are not easily automated. In this connection, it has been found that, in addition to presenting risk of failure, the steps of dispensing and applying liquid or paste are difficult to automate.
Accordingly, it is a general object of this invention to provide an improved die-attach method and structures made by such method.
Another object of the present invention is to provide such a die-attach method which avoids problems associated with the steps involved in the use of paste or liquid die-attach media.
Another object of this invention is to provide a die-attach method which can be automated.